Drainage systems provide a means for transporting fluid flow from surface areas to other areas such oceans, rivers, lakes, estuaries, streams and the like. Drain inlets or catch basins are the initial entry points of drainage systems.
Generally, a drain inlet comprises a walled structure having an open top for receiving fluid flow and one or more drain exits situated at its lower portion. The inlet is situated such that its top portion is at approximately surface level, and in many cases it is covered with a grate. Usually the drain exits are pipes exiting the drain inlet. Grates covering the top opening of the drain inlet serve to block larger items of debris contained in surface runoff, such as tree limbs and the like. However, smaller items of debris, sedimentation, pollutants and other contaminants pass readily through the grate and into the drain inlet and thereafter into the drainage system via the drain exits.
Although filtration systems for inhibiting the flow of debris, sediments, pollutants and other contaminants from entering the drainage system are desirable, it is important that the filtering system avoid restricting the ability of the drainage system to accommodate the desired volume of fluid flow. If the fluid flow, such as storm water runoff, is impeded, then flooding might occur. Accordingly, effective devices and systems are desired for inhibiting the entrance of debris, sedimentation, pollutants and other contaminants into drainage systems, while minimizing any restrictions to the capacity of the drainage system to receive fluid flow.